Robots and their parts : ISO 10218-1

Last edit: 10/07/2025

We all know that robots are the beating heart of robotic islands, and their use is becoming more and more widespread for the automation of industrial processes; knowing their importance, let us now analyze the parts from which it is composed.

The tool centre point

We can start from its end: from the tool central point, which is considered important for the robot’s safety functions:

[ISO 10218-1: 2025] 3.1.2 Sub-assemblies and components

3.1.2.11 tool centre point TCP: point defined for a given application (3.1.1.5) relative to the mechanical interface (3.1.2.7) coordinate system.
Note 1 to entry: The TCP setting defines the location of the TCP relative to the mechanical interface (3.1.2.7).

The TCP is a geometric concept: it is the point in 3D space that represents the tool tip or operational center of the end effector. It is used to define where the robot “acts” with respect to its coordinate system.

Physically, this point is not always visible or represented by a part, but:

It is sometimes materialized with a pin, ball, point, or marker, just to measure or verify it; it is also recorded in the robot software with coordinates (offsets) relative to the tool flange.

The End-Effector

It is the device mounted on the end of the robot limb, responsible for direct interaction with the environment or workpiece.

[ISO 10218-1: 2025] 3.1.2 Sub-assemblies and components

3.1.2.3 end-effector: device specifically designed for attachment to the mechanical interface (3.1.2.7) to enable the robot application (3.1.1.4) to perform its task
EXAMPLE Gripper, welding gun, spray gun.
Note 1 to entry: End-effectors are sometimes known as end-of-arm tooling (EOAT).

There are various types of end-effectors:

  • Mechanical grippers: Usually with 2, 3 or 5 “fingers,” they use mechanical locking to grasp parts. Ideal for rigid components, with good accuracy.
  • Suction cups/vacuum grippers: Use vacuum to lift flat or porous surfaces
  • Magnetic grippers: Perfect for ferrous materials, often with permanent or electromagnetic magnets .
  • Process-tools: Including: welding flashlights, paint nozzles, drilling, milling, chamfering tools
  • Sensors: Cameras, force/torque sensors, ultrasonic, laser; used as much for vision and measurement as for feedback in delicate manipulations
  • Advanced types: Adhesives (capillary, van der Waals), soft-grippers (rubber), cryogenics, ultrasonic levitation, laser grippers for micro-manipulation.

The end-effector is the “hand of the robot”-from a simple gripper to complex systems with tools and sensors. The choice depends heavily on various factors including the task it is to perform, the type of material and precision required, and the operating and regulatory environment.

The mechanical interface

In turn, the end effector could not have been assembled without the help of the mechanical interface, an interlock used to connect the actual structure of the robot, i.e., end effector + tool, to the robotic arm.

[ISO 10218-1: 2025] 3.1.2 Sub-assemblies and components

3.1.2.7 mechanical interface: mounting surface at the end of the manipulator (3.1.2.5) to which the end-effector (3.1.2.3) is attached.

The mechanical interface, as mentioned earlier, is the connection point between the robot and the end-effector, and serves to:

  • Provide physical support to the end-effector during the operational cycle.
  • Transmit forces, moments, energy, control signals and sometimes sensory feedback between robot and tool.

Transmitted through the mechanical interface are:

  • Pneumatic, electrical, hydraulic (for grippers or tools).
  • Command signals and feedback for integrated sensors.

It is crucial as it provides rigidity, which is essential for mechanical operations, modularity, overload protection and versatile power supply.

The manipulator

In order for this set of parts to be used you need a part that acts as a conduit with the actuator to allow the movements, this is the manipulator, or manipulator.

[ISO 10218-1: 2025] 3.1.2 Sub-assemblies and components

3.1.2.5 manipulator: mechanism consisting of an arrangement of segments, jointed or sliding relative to one another

The manipulator is the robotic arm, composed of a sequence of links (rigid segments) and joints (movement) that connect the base to the end-effector.

  • Links: rigid structures that determine the shape and scope of the operating space .
  • Joints: can be:
    • Revolute (revolute)
    • Prismatic
    • Spherical

Typically, a serial robot has 6 joints (6 DoFs), which are needed to position and orient the end-effector at each point in the space.

Each coupling includes:

Actuators (electric servomotors / PMSM) coupled with gearboxes, to convert electrical energy into motion with precision and force.

Gearboxes: increase torque and reduce speed, improving control and stability.
Encoders on motors for position and speed feedback in closed-loop control.

Each coupling includes:

  • Actuators (electric servomotors / PMSM) coupled with gearboxes, to convert electrical energy into motion with precision and force.
  • Gearboxes: increase torque and reduce speed, improving control and stability.
  • Encoders on motors for position and speed feedback in closed-loop control.

The connections between links and joints form a kinematic chain, which is divided into two:

  • Serial chain
  • Parallel chain

The actuator

This whole set of actions are ensured by an actuator that transforms electrical energy into actual motion.

 [ISO 10218-1: 2025] 3.1.2 Sub-assemblies and components

3.1.2.10 robot actuator: powered mechanism that converts energy to effect motion

Note 1 to entry: Energy can be electrical, hydraulic, pneumatic or more

The actuator is the “motor” of the manipulator: it converts electrical, hydraulic or pneumatic energy into motion (rotation or translation) and torque applied to the joint. There are several types, each with specific characteristics.

    • Electric
      • Servomotors: motors with encoders and closed-loop control, provide angular precision and responsiveness in robotic arms.
      • Stepper motors (steppers): rotate in discrete steps, useful for precise control without the need for encoders.
      • Brushless motors with harmonic gearbox: very common for achieving high torque with compact footprint.
  • Hydraulic
  • Pneumatic
  • Advanced and special
    • Piezoelectrics: require high micron accuracies but offer limited travel.
    • Shape Memory Alloy (SMA) and linear motors: used in soft or sub-µm precision robots.

The actuator operating principle as a whole is characterized by important aspects, conversionto energy, reduction, and closed-loop control.

The actuator is the vital center of robotic joints ensures the precise movement of the manipulator and supports the dynamic control of the robot.

Workpieces and the Payload

While handling parts for the work process, the robot manipulates parts referred to as workpieces, or workpieces. The assembly of these, or rather the mass of them, including the manipulator and end effector, constitute the payload.

 [ISO 10218-2: 2025] 3.1.2 Sub-assemblies and components

3.1.2.9 payload: mass of all that is attached to the manipulator (3.1.2.5), including the end-effector (3.1.2.3) and workpiece
Note 1 to

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